LG Refrigerator Error Code Er FS

Er FS indicates the control board has detected a problem with the freezer temperature sensor, specifically a short circuit or a disconnection in the sensor or its wiring. The board cannot read a valid temperature from the freezer thermistor and displays this code to alert you to the fault. The freezer may not cool correctly while this code is active.

You can continue using the refrigerator briefly, but it is not safe to leave it running unattended for an extended period with this code active. Without a functioning freezer sensor, the control board cannot regulate freezer temperature accurately, which puts frozen food at risk of thawing. Address the fault as soon as possible to avoid food spoilage.

Checking and reseating the wiring harness is a low-difficulty task that requires only unplugging the unit and accessing the freezer interior. Testing the thermistor with a multimeter requires basic familiarity with the tool but is manageable for most DIYers with the correct resistance spec from the service manual. Replacing the thermistor itself is also a relatively accessible repair. If the control board is at fault, that replacement is more involved, and a technician is advisable if you are not comfortable with control board work.

Start by unplugging the refrigerator, locating the freezer sensor wiring harness connector, and checking that it is fully seated. Reseating a loose connector often clears the code. If the connector is secure, inspect the wiring for visible damage or pinching. If the wiring looks intact, test the thermistor resistance with a multimeter and compare it to LG's specified values for that sensor at a known temperature. A thermistor that reads open or shorted needs to be replaced.

If the fix is simply reseating a loose connector, there is no parts cost at all. A replacement freezer thermistor for an LG refrigerator typically costs between $15 and $40 for the part. If a technician is needed, expect to pay a service call fee plus labor, usually totaling $100 to $200 depending on your area. A main control board replacement, if required, is significantly more expensive, often $150 to $300 for the part alone.